An electronic device such as a portable terminal having a display panel, generally, has a display panel arranged opposite to the opening of a housing and is constructed in such a way that the opening is closed by a protective panel. An electronic device like this has a waterproof structure in which the opening is hermetically closed by the protective panel. Constructions that are described in patent documents 1, 2, are example of this kind of waterproof structure that is publically known.
In recent years, in an electronic device having a touch panel for operating a display of a display panel, the display face of the display panel tends to be increased in size and the usage environment of a user is greatly changed as the size of the display face increases. For this reason, the cases where the electronic device gets wet or has an impact applied thereto have increased in number.
Further, as the size of the display face of the electronic device increases, the electronic device is limited by the kind of materials which can be combined for use in the electronic device according to the linear expansion coefficients of the materials of constituent members. Therefore, increasing the size of the display face of the electronic device makes it difficult to ensure adequate waterproof characteristics and durability. Hence, in the electronic device provided with a touch panel, in particular, are strongly requested improvements in the waterproof property and in the resistance to impact of the display face of the display panel.
A section view of an example of a waterproof structure relating to the present invention is shown in FIG. 1. As shown in FIG. 1, waterproof structure 101 relating to the present invention includes: a housing 107 having opening 108; liquid crystal display panel 110 which is arranged opposite to opening 108 in the housing 107; and protective panel 111 which is arranged outside housing 107 and which closes opening 108. Protective panel 111 is arranged in such a way as to protect the display face of liquid display panel 110.
Housing 107 is constructed of first outer case 107a and second outer case 107b which are engaged with each other. A portion in which first outer case 107a is engaged with second outer case 107b has O ring 113 fitted therein and hence has airtightness ensured. Protective panel 111 is arranged on the outer side of first outer case 107a and is bonded to the peripheral edge portion of opening 108 by double-sided adhesive tape 116 to thereby close opening 108.
Patent document 1: Japanese Utility Model Application Laid-Open No. 58-78685
Patent document 2: Japanese Patent Application Laid-Open No. 2005-333290